Apparatus for liquid cooling of specific computer components

ABSTRACT

Apparatus is provided for a heat transfer assembly for direct attachment to a high heat generating chip, which assembly includes a pump, air side heat exchanger mounted adjacent to a fan and a heat transfer plate which is attached to the high heat generating component for dissipating heat from such component under operating conditions. In another embodiment, apparatus is provided for dissipating heat from a hard disk drive including a U-shaped heat exchange clip resiliently mounted on opposite surfaces of a hard disk drive. In another embodiment, apparatus for dissipating heat from a hard disk drive includes a generally rectangular plate for mounting on the top or bottom of the hard disk drive. And, in another embodiment, apparatus is provided transferring heat from a vertical array of hard disk drives, which apparatus includes one or more panels interposed between adjacent vertically disposed hard disk drives.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/024,205,filed Feb. 17, 1998, now U.S. Pat. 6,333,847 which is a divisional ofapplication Ser. No. 08/775,143, filed Dec. 31, 1996 now abandoned,which is a continuation-in-part of application Ser. No. 08/674,018,filed Jul. 1, 1996, now U.S. Pat. No. 5,757,615.

STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to apparatus for liquid cooling byconduction of specific computer components mounted within a housing fora computer in order to reduce the operating temperature of suchcomponents.

2. Description of the Related Art

As certain components for computers, such as microprocessors or harddisk drives become more powerful and complex, while maintaining compactsize, more effective thermal management becomes necessary in order tomaintain desirable operating temperatures. It is well known thataccording to the Arrhenius equation, there is an exponential increase infailure rates with incremental increases in operating temperatures. Forexample, assuming a 1.0 eV activation energy, the failure rate doublesfor every 10° rise in operating temperature. Therefore, increase inpower of computer chips such as the Pentium® requires more effectiveheat management techniques to prevent undesirable rises in operatingtemperatures.

It is known to apply air-cooled fin modules directly to electroniccomponents in order to dissipate heat through conduction by use offinned heat exchangers and convection with such heat exchangers beingcooled by air flow. For example, Intel's 486 microprocessor was cooledby a conformal finned heat exchanger, and Intel's Pentium® chip has beencooled by finned type heat exchangers which have surface area extendingbeyond the actual contact surface area of the Pentium®, sometimes knownas extended surface heat exchangers. The operating power of certaincomponents such as newer versions of Pentium® chips of Intel has reachedlevels which require high volumes of forced ambient air to dissipategenerated heat; however, forced air to cool finned modules havelimitations in that there may be an upper limit to volumetric flow ofcooling air due to noise or other factors such as increased powerrequirements.

Cooling systems other than finned surface area exchangers are currentlyknown in the prior art. For examples Peltier coolers and heat pipes areknown. But, the potential height of Peltier coolers as well as therequirement for extra cooling load due to inherent inefficiencies reducethe probability for successful application to high heat load components.And, heat pipes have heat transfer capacity limitations due primarily tolosses in realizing connection to hot and cold thermodynamic reservoirs,but also due to limitations of heat transport due to internal designlimits.

It is also known to use cooling plates for circulating liquid coolant,which plates are mounted in contact with various power modules such astransistors, diodes and rectifiers. For example, the EG&G ComponentsDivision of Wakefield Engineering of Wakefield, Massachusettsmanufacturers sheet plates which are bent to conform, that is, crimpedabout cooling tubes and water-cooled solid copper blocks designed tocool pressure mounted rectifiers and SCR's dissipating up to 2 kw perdevice. The Wakefield cooled plates have several disadvantages in thatthere is significant thermal resistance across the interface between thecopper tube and the aluminum plate, and in that crimping of tubes insuch a manner has been found to lead to variations in cooling of up to50 percent.

A number of prior art patents are directed to the use of liquid coolantto cool electronic components, particularly in large main frame typecomputers. U.S. Pat. No. 5,159,529 utilizes a plastic internal coolingcore having mounted to it one or more cooling plates of copper toreceive various electronic components. However, the attachment ofcooling plates of copper to a plastic core may cause possible leakproblems due to material incompatibility. U.S. Pat. No. 5,144,532discloses the use of two oppositely positioned liquid cooling plateswhich are in contact with printed circuits positioned on opposite sidesof a multi-layer printed circuit board. U.S. Pat. No. 4,748,495discloses a liquid cooling module for a plurality of integrated circuitchips arrayed in uneven height wherein cooling fluid is routed eitherthrough a group of heat sinks or independently through each of a numberof heat sinks. And, U.S. Pat. No. 4,758,926 discloses utilizing heatsinks having microchannels to receive cooling fluid for cooling chips.

While the prior art encompasses the general use of cooling fluid orcoolant to cool electronic components, there remains a need to develop ahigh capacity cooling system for mounting within computer housings fordesktop and server size computers where the cooling system is in directcontact with the most powerful and highest heat generating electroniccomponents, such as more recent and more powerful versions of thePentium® processor and hard disk drives. It is accordingly an object ofthis invention to provide a cooling system specifically directed to suchcomponents.

BRIEF SUMMARY OF THE INVENTION

In accordance with various embodiments of this invention, apparatus isprovided for transferring heat from high heat generating electroniccomponents such as advanced, high powered computer chips and hard diskdrives. In one embodiment, such apparatus includes a generallyrectangular chassis having a plurality of components including a motherboard, with a processor chip being mounted in one of the processor slotson the mother board. A heat exchange assembly includes a power supplymounted in one corner of the chassis having a fan mounted adjacent tothe power supply. The heat exchange assembly is provided for dissipatingheat generated by the chip including an air to liquid heat exchangermounted on the chassis adjacent to the fan, a pump mounted on thechassis at a convenient point and a heat transfer plate having aconfiguration substantially identical to the bottom surface of the highheat generating chip. The heat transfer plate is connected to the airside heat exchanger and pump by suitable tubing lines so that a liquidcoolant can be transferred to the heat transfer plate in order to removeheat from the high heat generating chip, with the heated coolant beingcooled in the air side heat exchanger and returned by the pump to theheat transfer plate in a continues fashion.

In another embodiment of this invention, apparatus is provided forcooling an operating hard disk drive, including a generally U-shapedheat exchange clip for resilient mounting onto the sides of the harddisk drive container. The U-shaped clip has external liquid coolant flowloops attached on the outside of the clip in order to transfer heat fromthe hard disk drive. In another embodiment of cooling for an individualhard disk drive, apparatus includes a generally rectangular heattransfer plate having substantially the same dimensions as a surface ofa hard disk container for transferring heat from such container.

And, further apparatus is provided for transferring heat from a verticalarray or stack of hard disk drive units. Such apparatus includes one ormore panels mounted between adjacent, vertically positioned hard diskdrive units in order to remove heat from adjacent units simultaneously.

This summary of the invention is intended as a general description ofthe attributes of this invention, which will now be described in moredetail in the detailed description, with the claims to follow settingforth the subject matter sought to be patented.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic view of a computer illustrating the preferredembodiment of this invention for providing a liquid cooling medium to ahigh heat generating processor;

FIG. 2 is a schematic view illustrating a heat exchange plate formounting onto a high heat generating processor;

FIG. 3 is a side view illustrating an air to liquid heat exchanger forcooling liquid flowing from the heat exchanger plate of FIG. 2;

FIG. 4 is a perspective view of a clip-on heat exchanger for providingheat exchange liquid coolant to a hard disk drive;

FIG. 5 is a perspective view of the rear side of the clip-on hard diskdrive heat exchanger of FIG. 4;

FIG. 6 is a perspective view of a heat transfer plate for mounting onthe surface of a hard disk drive; and

FIG. 7 is a perspective view of the use of heat exchange panels forinsertion between adjacent, vertically stacked hard disk drive units.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings and in particular to FIGS. 1-3, apparatusgenerally designated as A is illustrated for continuously cooling a highheat generating component P such as the Pentium® manufactured by IntelCorporation, which generates high heat due to its power requirements.When the Pentium® chip was first developed by Intel, Intel proposed thatthe Pentium® chip be cooled by a combination of a heat sink and airflow, with the size of the heat sink and the amount of air flow beinginterrelated. Public specifications for early versions of the Pentium®chip included maximum power for a 66 MHZ Pentium® processor of a PGApackage type of 16 W, having a package size of 2.16″×2.16″ and a maximumcase operating temperature of 70° C. Intel further disclosed asspecifications that the maximum device junction temperature for such aPentium® processor was 90° C.

Within a typical computer housing, it is known that ambient air shouldbe in the range of 40° C. to 45° C., ambient air being defined as thetemperature of the undistributed ambient air surrounding the Pentium®package. For Intel, ambient temperature was typically measured at 12inches upstream from the package under investigation and in a systemenvironment, ambient temperature was defined as the temperature of theair upstream to the package and in its close vicinity.

With the advent of newer generations of the Pentium® processor and otherhigh operating temperature or high heat generating chips such asapplication specific integrated circuits (ASICS), which will becollectively referred to hereinafter as “high heat generatingprocessors” or “high operating temperature chips,” it is becomingincreasingly difficult to maintain such operating processors withindesired operating temperature limits utilizing only a combination ofheat sinks or finned heat exchangers subjected to air flow. Apparatus Aof this invention is directed to a cooling system utilizing liquid as acoolant for specifically maintaining high operating temperatureprocessors or chips within manufacturer's specified limits. Further, itis known that chip manufacturers typically reject or sell at reducedprices chips which exceed operating temperature specifications.Utilizing apparatus A of this invention may allow use of previouslyrejected chips which can be purchased at reduced rates.

Referring to FIG. 1, a computer housing generally designated as 10 isillustrated. The housing 10 is in a rectangular box form as iswell-known in the prior art. The exemplary housing 10 includes a bottom11, a first set of opposing sides 12 a and 12 b and a second set ofopposing sides 14 a and 14 b, all of which are interconnected or formedintegrally with the bottom 11. A chassis generally designated as 13 ismounted within the housing 10 in a known manner. The chassis 13 isgenerally rectangular so that the chassis has opposing sides (not shown,but parallel to and slightly smaller in dimension as the sides of thecomputer housing) to conform to the computer housing bottom 11 and sides12 a-b and 14 a-b and includes mother board 15.

As is known in the art, the mother board 15 is positioned adjacent tobottom 11 of housing 10 to mount the various computer components whichare utilized as known in the art. All the components necessary for afully operating computer will not be described herein but are fullyknown to those of ordinary skill in the field of computer design. Thecomponents which will be specifically identified herein are thosespecifically relevant to this invention.

The mother board 15 includes a series of slot mountings (not shown butknown in the art) which mount a series of “daughter” boards includingboards such as microprocessor board 16 which actually mounts thePentium® or other high heat generating processor. The advantage ofmounting the principal high heat generating processor P onto a removableboard 16 is that the computer may be enhanced by exchanging board 16 fora board containing a new and improved high heat generating chip. Otherdaughter boards such as a peripheral component interface board or avideo interface board are mounted and identified as 17 and 18. It isalso common to mount the processor chip in zero insertion force (ZIF) orlow insertion force (LIF) sockets. Housing door or opening 19 mounts oneor more bays for receiving floppy disk drives or compact disk drives asis known in the art. The rectangular structure generally designated at20 is the mounting location for one or more such peripheral componentunits.

A power supply 21 is mounted in the corner of the housing formed bysides 14 a and 12 b such that no coolant leak could flow into the powersupply primary side under any operating condition due to gravity orentrainment in the air flow. A computer cooling fan 22 is mountedadjacent to the power supply 21. A series of slots 23 are formed in theside or face 14 b in order to allow for the in flow or out flow of airfor circulation through the housing.

Apparatus A of this invention continuously provides liquid coolant tothe high operating temperature chip P and includes a pump generallydesignated as 30, an air-side heat exchanger generally designated as 32and a heat transfer plate 34. The pump 30, which may be mounted at anyconvenient location within the confines of the chassis 13, provides aclosed loop liquid coolant circulation system for pumping coolantbetween the air-side heat exchanger 32 and the plate heat exchanger 34.The air side heat exchanger 32 is illustrated in detail in FIG. 3. Theair side heat exchanger 32 can be any of a number of commerciallyavailable heat exchangers. In the current preferred embodiment heatexchanger 32 of FIG. 3 may be similar to a 720 series heat exchangerhaving a transfer capacity up to 18 kw sold by EG&G Division ofWakefield Engineering of Wakefield, Massachusetts. The series 720 heatexchanger 32 utilizes copper tubing 32 a which extends from inlet 32 cand is formed in a serpentine configuration which exits the unit atoutlet 32 b. A frame for mounting the serpentine configuration of thecopper tubing 32 a is generally rectangular in configuration anddesignated by the number 33, and is made of aluminum. The air side fins32 d are mounted within the aluminum frame 33 and attached to theserpentine configuration of copper tubing in a known manner. The unitcomes with an available standard Rotron Muffin Fan tm XL Model No. MX2A3or another fan unit 22 may be used as is known in the art. In any event,it is desirable to mount the air side heat exchanger 32 immediatelyadjacent to the fan unit 22 for greatest heat transfer efficiency toreduce the temperature of liquid coolant flowing therethrough. The pump30 to be utilized should have a diameter of no greater than 2.5 inchesand a length of no greater than 5.0 inches. The pump 30 should have aflammability rating of UL94 94V-2 and UL motor overload and lock rotorrating of UL 1950. For purposes of definition, the pump 30 has lowpressure entry port 30 a and a high pressure exit port 30 b.

The cooling plate 34 is illustrated schematically in FIG. 2. The coolingplate 34 is a rectangular, block of solid copper which receives a brasstubing line 35 at its outlet 34 b and brass tubing line 36 at its inlet34 c. The brass tubing lines 35 and 36 are shown in dashed lines in FIG.1 since the pump may be located at any available location within theconfines of the chassis 13. The copper block 34 is shown to have aU-shaped bore portion generally designated as 34 a drilled through theblock or otherwise formed. However, other configurations for the flow,including a serpentine flow path having multiple bores extending in thelong direction of the block may be utilized in order to effect greaterheat transfer. The overall dimensions of the copper block in terms oflength and width are to be designated to conform to the length and widthof the alloy material bottom surface or ceramic undersurface of thePentium® chip or other bottom surface of a high operating temperaturechip. The topography of the block surface to be in contact with thebottom surface of a high heat generating chip can be machined to conformto the bottom surface of this chip with interstitial application ofthermal grease or equivalent as known by the art to avoid air pockets.Rather than utilize a solid copper block, it is within the scope of thisinvention to utilize as a cooling plate 34 a hollow block having bottom,top and four sides formed of copper or brass with one or more internalbaffles running lengthwise part of the length of the housing topartition the housing into multiple chambers for purposes of providingfluid communication with the inlet tube 36 and the outlet tube 35. Thetubing should be brass or fire-resistant plastic and rated to requiredoperating conditions, and should have a flammability rating of UL62VW-1.

The liquid coolant may be water, or a mixture of 50 percent ethyleneglycol and water with known corrosion inhibitors. The liquid system willutilize connectors known in the art to provide a closed coolant systemwhich is sealed for life and is not field serviceable.

It is known that the electronic components mounted on the chassistypically raise the ambient temperature within the computer housing 10about 10° C. If is further known that high heat generating chips such asthe Pentium® have an operating temperature range of about 60-70° C. Theapparatus A of this invention is designed to cool the chip P to anoperating temperature within the range of about 55° C. in order to beable to use chips which currently are out of specification of certainchip manufacturers. This is accomplished by designing the size of theheat exchanger 32 and flow rate of the pump 30, taking intoconsideration the effective heat transfer of the cooling plate 34, suchthat sufficient heat will be transferred from the operating chip P toreduce the operating temperature to about 55° C. for worst caseoperating conditions, that is, to about 5° C. below the bottom of thetemperature operating range of the chip. The 55° C. assumes a roomambient temperature of 40° C. The required flow rate will vary dependingupon the particular processors, ASIC and/or hard drive cooled, but it isbelieved that the flow rate will be less than the prior art uses ofliquid cooling.

Referring to FIGS. 4-6, apparatuses B-1 and B-2 are illustrated andprovided for providing liquid coolant for reducing the operatingtemperature of hard disk drives. The hard disk drives such as drive D-1illustrated in FIG. 4 and drive D-2 illustrated in FIG. 6 have becomecommercially standard components in their mounting pattern and envelope.The drives D-1 and D-2 are mounted inside computer housings either aloneor in densely stacked arrangements (to be discussed with respect to FIG.7). Typically, the hard disk drives are cooled by air flow without heatsink provisions due to the type of packaging. Hard disk drives such asD-1 and D-2 come in two basic sizes, “half height” and “full height.”The only difference is that the half height hard disk drive isapproximately 1 inch high and the full height hard disk drive isapproximately 1.63 inches high. Hard disk drive assemblies are basicallybuilt of a steel container with a single printed wiring board (PWB) suchas designated as 50 in FIGS. 4 and 6 being screwed intimately to thebottom 51 a of the hard disk drive housing generally designated as 51.The other surfaces of the hard disk drive housing 51 include top 51 b,front and back sides 51 c and 51 d, respectively, and opposing sides 51e and 51 f. As is well-known in the art, the hard disk drive container51 contains a set of hard drive disks mounted on a spindle which rotatesat many thousands of rpm. The rotating action results in making theinternal hard drive container environment into a uniform temperature orwhat may be termed as “well-stirred vessel.” Hard disk drives such asD-1 and D-2 contain several temperature sensitive devices including butnot limited to the motor bearings.

It is known to cool hard disk drives in part through conduction coolingthrough their mounting rails, a techniques which is limited inefficiency due to the interface conductance loss through the rails andloss due to conduction throughout the length of the rails.

Referring to FIG. 4, apparatus B-1 is a clip-on heat exchanger forresilient mounting onto opposing surfaces of a hard disk drive D-1 unithousing 51. The clip-on heat exchanger 60 is formed of a generallyU-shaped spring clip 60 made of beryllium copper, phosphor bronze orother suitable metal. The U-shaped spring clip 60 is formed of first andsecond clip arms 60 a and 60 b which are integrally joined to the clipbase or back 60 c through two curved or arcuate integrally formedyieldable sections 60 d and 60 e. The U-shaped heat exchanger clip 60 isthus formed with sides 60 a and 60 b which are easily and resilientlyexpandable apart for insertion onto the sides 51 e and 51 f of the diskdrive housing 51 and thereafter are held in place due to the resilientcompressibility of the spring action of the clip itself.

Referring to FIGS. 4-5, the U-shaped spring clip includes openings 60 fand 60 g positioned in the arcuate sections 60 d and 60 f. Tubing inlet62 and tubing flow outlet 63 are mounted with the heat exchange clipback 60 c and sides 60 a and 60 b in order to cool the heat exchangeclip itself and thereby through conduction absorb heat from the diskdrive housing 51. Tubing inlet line 62 passes through a junction 64having a Y-shaped connection (not shown) to divide the inlet line intofirst and second inlet line portions 62 a and 62 b. Tubing outlet line63 is divided by a Y-shaped connection into tubing outlet line portions63 a and 63 b. Inlet lines 62 a and 62 b extend through heat exchangeclip openings 60 f and 60 g, respectively, and extend longitudinallyalong the length of each of the outer surfaces of sides 60 b and 60 a.The tubing portions 62 a and 62 b are attached to the sides 60 a and 60b by brazing at points 65. The tubing inlet lines such as 62 a makesU-turn at section 62 c and joins return coolant line 63 a, which extendsback to coolant outlet line 63. The heat exchange clip coolant inletline 62 extends to the pump outlet for a pump such as the pump 30 ofFIG. 1, and the heat exchange clip coolant outlet line 63 extends to theinlet of the air side exchanger such as 32 so that the heat exchanger 32in the pump 30 is part of the overall hard drive coolant system of FIGS.4-5 for continuously removing heat from the operating hard disk drive.

Referring now to FIG. 6, a hard disk drive D-2 is illustrated. Drive D-2has a housing identical to housing 51 of drive D-1 except that drive D-2is attached on one or more of its sides such as 51 e to mountings withinthe computer housing such that it is necessary to provide apparatus B-2to provide cooling to the hard drive. Apparatus B-2 includes a copperplate 70 which is rectangular in configuration and has a length andwidth which matches the top surface 5 b of hard drive D-2. Coolant inletline portion 71 a extends from an outlet line from the pump 30 (FIG. 1)other suitable pump and is mounted onto the top of the cooling plate 70by brazing at various points 65 as shown in FIG. 6 and extends in agenerally rectangular pattern around the perimeter of the cooling plate70 and terminates in an outlet portion generally designated 71 bintegrally formed with the inlet portion, such outlet portion 71 bextending to an inlet to the air side heat exchanger 32 or othersuitable air side heat exchanger, so that the pump 30 and air side heatexchanger of FIG. 1 from part of the heat exchange system B-2 of FIG. 6.One or more retainer clips generally designated as 72 are mounted on oneor more sides such as 51 c, 51 e and/or 51 f of the hard disk drive D-2in order to retain the cold or cooling plate 70 in position on the topsurface 51 b of the disk drive housing 51.

Referring to FIG. 7, apparatus B-3 is provided for cooling verticalarray of hard disk drives D-3, D-4, D-5 and D-6, which are verticallystacked upon each other and mounted to suitable computer mountings byscrew holes 80 such as well known rail-type mountings (not shown). Thevertical array of hard disk drives D-3 through D-6 will generatesubstantial heat which cannot be suitably cooled to desired operatingtemperatures through the use of conventional heat sinks and air cooling.Each of the hard disk drives D-3 through D-6 include a generallyrectangular, box-like housing or container having a top surface, abottom surface and opposing sides surfaces and thus the same designationfor each housing for each of the containers for drive units D-3 throughD-6 may be used. Air cooling is undesirable as a technique due to thehigh volumes of air necessary to cool, which would require undesirablereliability risk due to possible fan failure and which will causeacoustical problems, also. The cooling system B-3 is provided forinterposition or sandwiching between adjoining hard disk drives such asD-3 or D-4 for providing for conductive heat transfer of heat fromadjacent disk drives to a series of flexible heat exchange structures orpanels 81.

Each of the flexible heat exchange structures 81 is made of hollow,relatively thin, sheet-like panel in rectangular form and is filled witha coolant liquid such as a mixture of 50% water and 50% ethylene glycol.The flexible heat exchange structure 81 has a peripheral seal section 81a which extends about the rectangular periphery to form a cavity orchamber therein. The interior of the flexible heat exchange structure isformed of five flexible body layers which include, from top to bottom, atop layer, a middle layer and a bottom layer of a polyamide filmmaterial, representatively a material manufactured by the Dupont Companyunder the name “KAPTON,” with intervening layers of an FEP fluorocarbonfilm material, representatively a material manufactured by the DupontCompany under the tradename “TEFLON.” Passages are provided through thecentral area between the two sheets of fluorocarbon film material byproviding round interbonded sections 81 b at spaced locations in orderto provide a generally U-shaped flow path 82 through the flexible heatexchange panel or structure 81. The points of film attachment 81 b alsoserve to hold the outer sheets against undesirable expansion orballooning, which may provide undesired forces against the printedwiring board 50 side of the drives. Instead, the force can be controlledto provide only beneficial heat transfer pressure to enhance the heattransfer contact with the surface of the hard disk drives. The locationof the round interbonded sections may be varied in order to providedifferent flow paths but in the embodiment illustrated, the interbondedsections 81 b are located at four points in a line along three linesrunning a longitudinal direction of the pad 81.

For further description of the manufacture of such a flexible heatexchange panel, Applicant incorporates by reference U.S. applicationSer. No. 08/674,081 listing as inventors Messrs. Daniel N. Donahoe andMichael T. Gill, which patent application was filed on Jul. 17, 1996 andassigned to the same assignee as herein, Compaq Computer Corporation.While the entire disclosure, specification, claims and drawings areincorporated herein by reference for purposes of enabling descriptionand for support for claiming, Applicant specifically directs attentionto the disclosure relating to FIGS. 3-7, and to the description of thecross-sectional flow passages found on pages 9-12, and referring inparticular to FIGS. 3 and 4. It is also feasible to use a moresimplified panel structure having two adjoining layers of suitableflexible plastic material sealed at their periphery and having multiplepoints where the sheets are heat welded together internally of thesealed rim.

Each of the flexible heat exchange panels 81 includes a coolant entranceor inlet 81 c and a coolant outlet 81 d. With the panels 81 positionedor sandwiched between adjacently stacked hard disk drives such as D-3and D-4, the coolant flow outlets 81 d of each panel 81 are connected toa central return manifold 85 through connections 85 a, 85 b and 85 c. Asimilar inlet manifold 87 connects together the inlets 81 c for each ofthe interposed or sandwiched flexible cooling panels 81. The inletmanifold 87 is then attached to the outlet to a suitable pump such asthe pump 30 of FIG. 1. The outlet manifold 85 is suitably connected tothe inlet of an air side heat exchanger such as the air side heatexchanger 32 disclosed in FIGS. 1 and 3.

The expansion of the panels during operation, as the result of fluidpressure, has another beneficial feature, which is that the drives areheld more tightly in position during operation; and, when the panels aredeflated, the drives are more easily removed.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the detailsof the illustrated apparatus and construction and method of operationmay be made without departing from the spirit of the invention. Forexample, it is within the scope of this invention to combine the variousheat transfer embodiments of this invention for use within a singlecomputer. Apparatus A of FIGS. 1-3 can be used to cool multiple chips byproperly sizing the pump 30, fan 22 and the air side heat exchanger 32to provide suitable cooled liquid coolant to more than one heat transferplate 34 simultaneously. Further, the pump 30, fan 22 and air side heatexchanger 32 may be suitably sized to cool the hard disk drive housing51 using the U-shaped clip 60 of apparatus B-1 of FIGS. 4-5 or using theheat transfer plate 70 of apparatus B-2 of FIG. 6 in conjunction withthe system of FIGS. 1-3. Or, the system B-3 for cooling the verticalarray of disk drives D-3 through D-6 of FIG. 7 can be combined with thecooling system A of FIG. 1-3. Further, disk cooling apparatus B-1 andB-2 can be used with the air side heat exchanger 32 and pump 30 of FIGS.1-2. Or, any other combination of any of A, B-1, B-2 and/or B-3 can beused with a single pump, air side heat exchange assembly.

The foregoing disclosure and description of the preferred embodiment areillustrative and explanatory thereof, and various changes in thecomponents, circuit elements, circuit configurations, and signalconnections, as well as in the details of the illustrated circuitry andconstruction and method of operation may be made without departing fromthe spirit and scope of the invention.

We claim:
 1. Electronic apparatus, comprising: a generally rectangularchassis having first and second sets of opposing sides; a plurality ofelectronic components mounted on said chassis, including a hard diskdrive, said hard disk drive having a generally rectangular box-likecontainer; a heat exchange system for said hard disk drive, including: agenerally U-shaped heat exchange clip including first and second armsintegrally formed with a base; a coolant loop mounted with said U-shapedheat exchange clip, said coolant loop including a first loop sectionattached to said first arm of said heat exchange clip and a second loopsection attached to said second arm of said heat exchange clip forcirculating liquid coolant to absorb heat transferred from said harddisk drive container to said first and second arms of said heat exchangeclip; said arms of said U-shaped clip being resiliently formed with saidbase for insertion over said hard disk drive container in resilientengagement therewith; and a closed circulation system for circulatingliquid coolant to said cooling loop mounted on said U-shaped clip andreducing the temperature of said coolant circulating from said coolingloop before circulating said coolant to said cooling loop.
 2. Electronicapparatus of claim 1, wherein the arms of the U-shaped clip areintegrally joined to the clip base or back through 2 curved or arcuateintricately formed yieldable sections.
 3. Electronic apparatus of claim1, wherein the arms are easily and resiliently expendable apart forinsertion over the hard disk drive container.
 4. Electronic apparatus ofclaim 1, wherein the arms are held in place due to resilientcompressibility of spring action of the clip.
 5. Electronic apparatus ofclaim 1, wherein the U-shape heat exchange clip comprises berylliumcopper, phosphor bronze, or other suitable metal.
 6. Electronicapparatus of claim 1, wherein heat is absorbed through conduction ofthermal energy from the hard disk drive container.
 7. Electronicapparatus of claim 6, wherein the arms are integrally joined to the clipbase or back through 2 curved or arcuate intricately formed yieldablesections.
 8. Electronic apparatus of claim 6, wherein the arms areeasily and resiliently expandable apart for insertion over the hard diskdrive container.
 9. Electronic apparatus of claim 6, wherein the armsare held in place due to resilient compressibility of spring action ofthe clip.
 10. Electronic apparatus of claim 1, wherein the coolant loopcomprises a tubing inlet and a tubing outlet mounted with the heatexchange clip base and sides.
 11. Electronic apparatus of claim 1,wherein the coolant loop is adapted to cool the clip.
 12. Electronicapparatus of claim 1, wherein the coolant loop is provided with inlettubing divided into first and second inlet line portions.
 13. Electronicapparatus of claim 1, wherein the coolant loop is provided with outlettubing divided into first and second outlet line portions. 14.Electronic apparatus of claim 1, wherein the coolant loop is providedwith inlet lines that extend longitudinally along the length of thearms.
 15. Electronic apparatus of claim 1, wherein the coolant loops areprovided with tubing portions attached to the arms by braising. 16.Electronic apparatus of claim 1, wherein the coolant loop is providedwith a tubing inlet line that comprises a u-turn and joins a returncoolant line that extends back to a coolant outlet line.
 17. Electronicapparatus of claim 1, wherein the heat exchange clip is provided with acoolant inlet line that extends to a pump outlet.
 18. Electronicapparatus of claim 1, wherein the heat exchange clip is provided with acoolant outlet line that extends to an inlet of an air side exchanger.19. Electronic apparatus of claim 1, wherein the heat exchanger iscomprised in a pump and is part of an overall hard drive system adaptedto continuously remove heat from the hard disk drive when operating.